After watching with interest your Home page comments on the webtrees forum and your theme development work, I am pretty sure I am in-tune with your thoughts about the use of the homepage.
What I had failed to fully understand about the kiwitrees theme was that the Home page top/main/ ex-“left” was fixed in size and that any blocks in the bottom / ex-“right” would scroll. Once that picture finally got through to me, I was able to make a Home page that I was happy with.
One thing is obvious, a Home page built for the kiwitrees theme doesn’t necessary translate into a Home page suitable for the other themes. My solution is to make the kiwitrees theme the default and the users who choose another theme will just have to live with it!